This invention relates to medical devices for sensing and measuring biological activity. More particularly, this invention relates to portable bio-sensors, including self-contained bio-sensors, capable of sensing and measuring cardiopulmonary activity.
A large number of chronic diseases are related to the dysfunction of the cardiopulmonary system. Modern lifestyles and environments predispose individuals to chronic obstructive pulmonary disorders (such as asthma and chronic obstructive pulmonary disease) and ischemic heart disease. Moreover, the cardiopulmonary system is functionally interconnected in many respects, such that alterations in heart function are sometimes associated with changes in the lungs.
The prevalence of heart and lung disorders has led to the development of many devices for detecting and monitoring dysfunction in these organ systems. An example of such a device is the spirometer, which is an instrument for collecting data about breathing capacity and other pulmonary functions. Spirometers are utilized for diagnosis of lung diseases and conditions, such as asthma, chronic bronchitis, emphysema, and other chronic obstructive pulmonary disorders (COPD); black lung disease, asbestosis, and other occupational lung diseases; and cystic fibrosis and other congenital diseases.
Spirometers are often large, bulky devices located in a hospital, doctor""s office, or other clinical setting. In recent years, however, some portable spirometers have been designed and manufactured. These previously known portable spirometers share a similar design based around a single tube having a mouthpiece and an exhaust port. A person using a portable spirometer blows air into the mouthpiece, through the tube (where the airflow is measured by one or more sensors), and out the exhaust port. Raw data collected by the spirometer can be used to determine various spirometric parameters in a Pulmonary Function Test (PFT), such as vital capacity (VC), which is the maximum volume of air that can be expired slowly after a full inspiratory effort; forced vital capacity (FVC), which measures the volume of air expelled from the lungs with maximal force; tidal volume (TV), which measures the volume of air inspired or expired with each breath; total lung capacity (TLC), which is the total volume of air within the chest after a maximum inspiration; peak expiratory flow (PEF), which is a measure of the highest airflow rate from the lungs during forced exhalation; maximal voluntary ventilation (MVV), which is the volume of air expired during breathing at the maximal TV and respiratory rate for twelve seconds; and forced expired volume during the first second (FEV1), which is the volume of air forcibly expelled in one second of time. Other PFTs are disclosed in Beers, M. H. and Berkow, R. (eds), The Merck Manual of Diagnosis and Therapy (Merck Research Laboratories, Whitehouse Station, N.J., 1999), chapter 64.
Previously known spirometers, including portable spirometers, do have some limitations, however. For example, some spirometers can measure only a single parameter (such as only PEF), while other spirometers have a single tube of a fixed diameter and can accurately measure only airflow rates within a certain range. Moreover, most spirometers are limited to collecting only spirometric data and not any other potentially useful physiological data.
Disclosed is a sensor device for obtaining cardiopulmonary data from a subject. The sensor device includes an elongated housing having a proximal end, a distal end, and a lumen. The lumen can be divided into one or more airflow tubes. The proximal housing end defines a respiratory port that is in fluid communication with the lumen, and an airflow port is defined in the housing adjacent the distal end of the lumen. The airflow port also is in fluid communication with the lumen.
An airflow sensor is positioned within the lumen and is capable of measuring pulmonary airflow through the lumen as the subject exhales or inhales. Also positioned within the lumen is a non-spirometric cardiopulmonary activity sensor. A data processor is operably coupled to both the airflow sensor and the non-spirometric cardiopulmonary activity sensor. Thus, the sensor device is capable of integrated collection of cardiopulmonary data obtained via the airflow sensor and the non-spirometric cardiopulmonary activity sensor.